Apparatus for rectifying alternating currents



June 4, 1940. G. sLAYTER APPARATUS FOR RECTIFYING ALTERNA'I'ING CURRENTS Filed Feb. 12. 1938 TToRNEY 2 Patented June 4, 1940 UNITED STATES PATENT FFICE Games Slayter, Newark, Chio, assignor to Electronic Research Corporation,

corporation of Ohio Application February 1 8 Claims.

My invention relates broadly to rectication systems for alternating current and more particularly to a method and apparatus for producing rectified current from high voltage alternatt ing current.

One of the objects of my invention is to provide an improved and simplified inexpensive system for rectifying high voltage alternating current embodying simplified and relatively inexpensive equipment.

Another object of my invention is to provide a system of rectiiication in which an arrangement of discharge points in spacial relation to a target at atmospheric pressure is biased to secure rectification of applied energy.

Other and further objects of my invention are the provision of high Voltage rectification systems which will remain at relatively low operating temperature While in use and oiier minimum electrical loss, as set forth more fully in the specification hereinafter following by reference to the accompanying drawing in which:

Figure 1 is a schematic wiring diagram showing one form of high voltage rectication system of my invention; Fig. 2 shows a characteristic curve of. the rectifier circuit and illustrates the manner in which an applied battery source effects a displacement of the eliective eld at the emitting tips of the rectifier; Fig. 3 represents the characteristic curve of the rectier with respect to current drawn from the emitters to the plate electrode, in the absence of the control electrode, as a function of voltage; Fig. 4 shows the characteristic curves and illustrates the current drawn from the emitters to the plate when a control electrode is employed between the emitters and the plate and is connected to the emitter; Fig. 5 shows the characteristic curves of the current as a function of. voltage between the emitters and the plate with a biasing potential applied between the emitters and the control electrode resulting in a displacement of the curves illustrated in Fig. 4; Fig. 6 illustrates the characteristic of the sine wave applied Voltage in time plotted downwardly; and Fig. '7 shows the characteristics of the rectied current obtained at the output of the rectifier of my invention.

My invention is directed to a high voltage rectiiication system which makes use of rectification properties' of a three-electrode arrangement at approximately atmospheric pressures utilizing electric and ionic discharge from points towards a target electrode and wherein selected bias potential is applied between the points and one of the electrodes.

Newark, Ohio, a

2, 1938, Serial No. 190,308

(Cl. V- 363) The arrangement of. electrodes at approximately atmospheric pressures may be made to function as a rectiiier when one of the electrodes is charged positively, for example, with respect to the discharge points, and the external circuit connected therewith will pass current only in the one direction up to such voltages that the maximum negative field transmitted through the grid from the target electrode to the discharge points does not exceed the value at which positive emission sets in from the discharge points. My invention has numerous applications in circuits such as full wave rectiiiers, potential doublers, inverters and in other high voltage circuits where the use of high vacuum electron tubes and mercury arc rectiiers is either expensive or impractical.

Referring to the drawing in more detail, reference character l designates the input circuit to the high voltage rectier constituted by a primary winding of transformer 2. The secondary winding of transformer 2 is indicated at 3 having one end connected to the load at 4 and the other end 5 connected to the discharge 'electrode 6. The discharge electrode 6 comprises a multiplicity of discharge points `directed toward a target electrode l with a control electrode 8 interposed therebetween. The control electrode 8 has a bias potential impressed thereon by means of the battery 9 or other source of D. C. potential, the positive terminal of which is connected with control electrode 8 and the negative side of which is connected with the discharge electrode 6.

The circuit E, l, B, functions as a rectifier as soon as the control electrode becomes positive with respect to the discharge electrode 6, and will pass current only in the one direction, up to such voltages that the maximum negative field transmitted to discharge points 6 from target 'I does not exceed the value at which positive emission sets in from discharge points 6.

I have illustrated the characteristic and performance curves of the rectifier system of my invention in Figs. 2-7. Fig. 2 shows the characteristic curve of the rectier circuit wherein the ordinates represent magnitude of current and the abscissa toward the left represents the positive voltage on the points of the discharge electrode 6 while the abscissa toward the right represents the negative voltage on the discharge points. The battery source 9 eiiects a displacement of the eiiective eld at the emitting tips of the discharge electrode 6 to correspond to a voltage shift in curve Hl by the e@ curve. Curve ll represents the applied alternating current at the input to the rectier. Curve l2 represents the effective eld at the emitting tips with increments of` positive voltage on the emitting tips.

The characteristic curves in Fig. 3 represent the current drawn from the emitters B to the plate 'i in the absence of any control electrode 8 as a function of voltage. Curve Ill shows the change in magnitude of current for increments of negative voltage changes on the points l while curve I5 shows the change in magnitude of current for increments of positive voltage changes on the points for the condition in which a control electrode is absent.

Fig. 4 represents the characteristic curves of the current drawn from the emitters 6 to the plate 'l when the control electrode il is interposed between the emitters t and the plate l and the control electrode grounded. The abscissa for curve E4 (value of' voltage) is increased for any point over the abscissa for curve lli (value of voltage) of the point for the corresponding phase in Fig. 3 by a factor' mu known as the ampliiication factor in three-electrode vacuum tubes. The same term may be properly applied here. The increase in voltage which results from introducing the control electrode between the emitters @i and the plate i' is marked, as will be seen by comparing the value A in Fig. 3 with the value B in Fig. 4. A corresponding change occurs with respect to the characteristic curve l5 of Fig. 4 as compared to curve i5 of Fig. 3 showing the increase of the positive voltage increments on the discharge point E resulting from the introduction of control grid 3 between emitters l and plate 1.

Fig. 5 shows the current as a function of Voltage between the emitter G and plate i with the battery 9 applied between control electrode 3 and emitters ii. It will be observed that each point on the curves Hi and i5 has been displaced in value of' voltage from the voltage of the corresponding points on curves Hl and l5 in Fig. 4 by a value Eo which is equal to the voltage of battery source 9 multiplied by the amplification factor mu.

In Fig. 6 I have shown the characteristic of the sine wave applied voltage at curve lli with time plotted downwardly as ordinates compared with voltage plotted as abscissa.

Fig. 'l' shows the characteristics of the rectified current obtained from the output of the rectiiier of my invention, the uni-directional current pulses being represented at Vi with current plotted as abscissa and ordinates plotted as time.

I realize that there are a variety of methods of fabricating, shaping and spacing the electrodes constituting the rectier for producing the maximum useful asymmetry of' characteristic and I intend to include all such modications Within the scope of my invention. Moreover, I am fully aware there are numerous applications of my invention as hereinbefore recited. I therefore desire it to be understood that I intend no .j limitations upon my invention other than may be imposed by the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is as follows:

1. A high voltage rectifier comprising in coinbination, a target electrode, a discharge point directed toward said target electrode, means for establishing an alternating potential between said target electrode and said discharge point under conditions oi substantially atmospheric pressure, disposed between said target a control electrode electrode and said discharge point, and means for maintaining said control electrode at a positive potential with respect to the discharge point for passing current in one direction only from the target electrode to the load.

2. A high voltage rectier comprising in combination, a target electrode, a control electrode and a discharge point operative under conditions of substantially atmospheric pressure, an input circuit connected to the source of alternating current to be rectied, a connection from said input circuit through said discharge point and said target with a load, and means for maintaining said control electrode at a positive potential with respect to said discharge point for passing current in one direction only with respect to said target electrode to the load.

3. A high voltage rectifier comprising in combination, a discharge point, a control electrode and a target electrode maintained under conditions of substantially atmospheric pressure, a source of alternating current to be rectied, a connection from one side of said source to said discharge point, a connection from the other side of said source through a load to said target, and means for maintaining said control electrode at a positive potential with respect to said discharge point for uni-directionally passing current from said target with respect to the load.

4. A high voltage rectifier comprising in combination, a discharge point, a control electrode and a target electrode maintained under conditions of substantially atmospheric pressure, a source of alternating current to be rectified, a connection from one side of said source to said discharge point, a connection from the other side of said source through a load to said target, and a source of potential having its positive side connected to said control electrode and its negative side connected to said discharge point for maintaining said control electrode at a positive potential with respect to said discharge point for unidirectionally passing current from said target with respect to the load.

5. A rectifier comprising point and plate electrodes, a control electrode adjacent said point electrode, and a source of potential having its negative side connected with said point and its positive side connected with said control electrode, said rectifier being operative in an atmosphere at substantially atmospheric pressure.

6. A rectifier comprising point and plate electrodes, and a control electrode adjacent said point electrode, said electrodes coacting Linder conditions of substantially atmospheric pressure, and

mean for biasing said control electrode at a predetermined fixed potential with respect to the potential of said point electrode in the same sign as the potential of said plate electrode for facilitating discharge from said point electrode to said plate electrode for producing a unidirectional current.

'7. A high voltage rectiiier comprising in combination, a target electrode, a multiplicity of discharge points extending toward said target electrode, means electrically interconnecting saidI multiplicity of discharge points, means for establishing an alternating potential between said target electrode and said multiplicity of discharge points under conditions of substantially atmospheric pressure, a control electrode disposed adjacent said target electrode and said multiplicity of discharge points, and means for maintaining said control electrode at a positive potential with respect to the multiplicity of discharge points charge points, a series circuit extending between said control electrode and said multiplicity of discharge points, and a source of potential disposed in said series circuit for maintaining said control electrode at a predetermined potential with respect to the multiplicity of discharge points and in opposite sign to the operating potential of said discharge points for passing current in one direction only from the target electrode to the load.

GAMES SLAYTER. 

